Samba into kernel

[David Lee]

On Mon, 25 Mar 2002, Urban Widmark wrote:

> [...]
> I don't think how the interface is published matters. What matters is how
> things are used or linked. If you haven't already you should read the GPL
> FAQ and/or look for a list/newsgroup place where licensing is discussed
> (I'm sure there is one).

(I had read the GPL etc.  Of course, not being a lawyer, I make no claim 
to fully understand it...)

Thanks for your reply.  A few detailed comments follow.

I took up your suggestion and sent a posting to the "gnu.misc.discuss" 
newsgroup.  There has been some follow-up, which looks reasonably
promising.

> * http://www.gnu.org/licenses/gpl-faq.html#WritingFSWithNFLibs
> 
> It is allowed to make a GPL'ed program use a standard library or make
> syscalls to the kernel without requiring those to be GPL.

Thanks for the info.  (The whole of GNU, e.g. gcc, gmake, autoconf,
libtool, etc. depends on this out here in non-GNU-OS-land!) 

> This is a "special exception" and is not really allowed by the other parts
> of the GPL. You couldn't distribute (use/compile?) samba for Solaris
> without this exception because the libc would be mapped into the memory
> space and added to the program.
> 
> The GPL regards the program + the linked libs as one "work".

Fine.  But that would apply the same in both userspace and kernelspace
wouldn't it?  Am I missing some subtle distinction here?

> * http://www.gnu.org/licenses/gpl-faq.html#GPLPluginsInNF

An interesting, though inconclusive, read.  And there is an explicit
"exception" mechanism to facilitate a GPL "plug-in" into a non-free
progam.  (And for us, the main "program" is itself the other allowed
exception of the OS.)

> The author can give permission for you to do non-GPL things with the code
> or relicense things. Problem might be to get ok from all authors and even
> to identify them and know which ones need to say ok.

But would we be doing a "non-GPL" thing?  We'd still be within GPL
wouldn't we?

Let me re-state the basic idea:

Current:  Our GPL Samba product currently uses one set of interfaces onto
the OS and the OS libraries (e.g. Solaris man(2) and man(3)).  This is
explicitly OK under GPL.

Proposal:  We adjust our GPL product to allow a site to choose a different
set of interfaces (e.g. Solaris man(9) DDI/DDK) into that same OS/library
set.

In other words, two alternate but equivalent interfaces, onto the same
non-free, but GPL-permitted, program (OS and libraries). 

Question:  What, if anything, in the GPL or its FAQ, would force a
distinction between these intended-equivalent things?   And how?

Take a look at the emerging thread on "gnu.misc.discuss".

Best wishes.

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